1 package DBIx::Class::ResultSet;
9 use Carp::Clan qw/^DBIx::Class/;
12 use DBIx::Class::ResultSetColumn;
13 use DBIx::Class::ResultSourceHandle;
16 use base qw/DBIx::Class/;
18 __PACKAGE__->mk_group_accessors('simple' => qw/_result_class _source_handle/);
22 DBIx::Class::ResultSet - Represents a query used for fetching a set of results.
26 my $users_rs = $schema->resultset('User');
27 my $registered_users_rs = $schema->resultset('User')->search({ registered => 1 });
28 my @cds_in_2005 = $schema->resultset('CD')->search({ year => 2005 })->all();
32 A ResultSet is an object which stores a set of conditions representing
33 a query. It is the backbone of DBIx::Class (i.e. the really
34 important/useful bit).
36 No SQL is executed on the database when a ResultSet is created, it
37 just stores all the conditions needed to create the query.
39 A basic ResultSet representing the data of an entire table is returned
40 by calling C<resultset> on a L<DBIx::Class::Schema> and passing in a
41 L<Source|DBIx::Class::Manual::Glossary/Source> name.
43 my $users_rs = $schema->resultset('User');
45 A new ResultSet is returned from calling L</search> on an existing
46 ResultSet. The new one will contain all the conditions of the
47 original, plus any new conditions added in the C<search> call.
49 A ResultSet is also an iterator. L</next> is used to return all the
50 L<DBIx::Class::Row>s the ResultSet represents.
52 The query that the ResultSet represents is B<only> executed against
53 the database when these methods are called:
73 =head2 Chaining resultsets
75 Let's say you've got a query that needs to be run to return some data
76 to the user. But, you have an authorization system in place that
77 prevents certain users from seeing certain information. So, you want
78 to construct the basic query in one method, but add constraints to it in
83 my $request = $self->get_request; # Get a request object somehow.
84 my $schema = $self->get_schema; # Get the DBIC schema object somehow.
86 my $cd_rs = $schema->resultset('CD')->search({
87 title => $request->param('title'),
88 year => $request->param('year'),
91 $self->apply_security_policy( $cd_rs );
96 sub apply_security_policy {
105 =head3 Resolving conditions and attributes
107 When a resultset is chained from another resultset, conditions and
108 attributes with the same keys need resolving.
110 L</join>, L</prefetch>, L</+select>, L</+as> attributes are merged
111 into the existing ones from the original resultset.
113 The L</where>, L</having> attribute, and any search conditions are
114 merged with an SQL C<AND> to the existing condition from the original
117 All other attributes are overridden by any new ones supplied in the
120 =head2 Multiple queries
122 Since a resultset just defines a query, you can do all sorts of
123 things with it with the same object.
125 # Don't hit the DB yet.
126 my $cd_rs = $schema->resultset('CD')->search({
127 title => 'something',
131 # Each of these hits the DB individually.
132 my $count = $cd_rs->count;
133 my $most_recent = $cd_rs->get_column('date_released')->max();
134 my @records = $cd_rs->all;
136 And it's not just limited to SELECT statements.
142 $cd_rs->create({ artist => 'Fred' });
144 Which is the same as:
146 $schema->resultset('CD')->create({
147 title => 'something',
152 See: L</search>, L</count>, L</get_column>, L</all>, L</create>.
156 If a resultset is used in a numeric context it returns the L</count>.
157 However, if it is used in a booleand context it is always true. So if
158 you want to check if a resultset has any results use C<if $rs != 0>.
159 C<if $rs> will always be true.
167 =item Arguments: $source, \%$attrs
169 =item Return Value: $rs
173 The resultset constructor. Takes a source object (usually a
174 L<DBIx::Class::ResultSourceProxy::Table>) and an attribute hash (see
175 L</ATTRIBUTES> below). Does not perform any queries -- these are
176 executed as needed by the other methods.
178 Generally you won't need to construct a resultset manually. You'll
179 automatically get one from e.g. a L</search> called in scalar context:
181 my $rs = $schema->resultset('CD')->search({ title => '100th Window' });
183 IMPORTANT: If called on an object, proxies to new_result instead so
185 my $cd = $schema->resultset('CD')->new({ title => 'Spoon' });
187 will return a CD object, not a ResultSet.
193 return $class->new_result(@_) if ref $class;
195 my ($source, $attrs) = @_;
196 $source = $source->handle
197 unless $source->isa('DBIx::Class::ResultSourceHandle');
198 $attrs = { %{$attrs||{}} };
200 if ($attrs->{page}) {
201 $attrs->{rows} ||= 10;
204 $attrs->{alias} ||= 'me';
206 # Creation of {} and bless separated to mitigate RH perl bug
207 # see https://bugzilla.redhat.com/show_bug.cgi?id=196836
209 _source_handle => $source,
210 cond => $attrs->{where},
219 $attrs->{result_class} || $source->resolve->result_class
229 =item Arguments: $cond, \%attrs?
231 =item Return Value: $resultset (scalar context), @row_objs (list context)
235 my @cds = $cd_rs->search({ year => 2001 }); # "... WHERE year = 2001"
236 my $new_rs = $cd_rs->search({ year => 2005 });
238 my $new_rs = $cd_rs->search([ { year => 2005 }, { year => 2004 } ]);
239 # year = 2005 OR year = 2004
241 If you need to pass in additional attributes but no additional condition,
242 call it as C<search(undef, \%attrs)>.
244 # "SELECT name, artistid FROM $artist_table"
245 my @all_artists = $schema->resultset('Artist')->search(undef, {
246 columns => [qw/name artistid/],
249 For a list of attributes that can be passed to C<search>, see
250 L</ATTRIBUTES>. For more examples of using this function, see
251 L<Searching|DBIx::Class::Manual::Cookbook/Searching>. For a complete
252 documentation for the first argument, see L<SQL::Abstract>.
254 For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
260 my $rs = $self->search_rs( @_ );
261 return (wantarray ? $rs->all : $rs);
268 =item Arguments: $cond, \%attrs?
270 =item Return Value: $resultset
274 This method does the same exact thing as search() except it will
275 always return a resultset, even in list context.
283 $attrs = pop(@_) if @_ > 1 and ref $_[$#_] eq 'HASH';
284 my $our_attrs = { %{$self->{attrs}} };
285 my $having = delete $our_attrs->{having};
286 my $where = delete $our_attrs->{where};
290 my %safe = (alias => 1, cache => 1);
293 (@_ && defined($_[0])) # @_ == () or (undef)
295 (keys %$attrs # empty attrs or only 'safe' attrs
296 && List::Util::first { !$safe{$_} } keys %$attrs)
298 # no search, effectively just a clone
299 $rows = $self->get_cache;
302 my $new_attrs = { %{$our_attrs}, %{$attrs} };
304 # merge new attrs into inherited
305 foreach my $key (qw/join prefetch +select +as/) {
306 next unless exists $attrs->{$key};
307 $new_attrs->{$key} = $self->_merge_attr($our_attrs->{$key}, $attrs->{$key});
312 (@_ == 1 || ref $_[0] eq "HASH")
314 (ref $_[0] eq 'HASH')
316 (keys %{ $_[0] } > 0)
324 ? $self->throw_exception("Odd number of arguments to search")
331 if (defined $where) {
332 $new_attrs->{where} = (
333 defined $new_attrs->{where}
336 ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_
337 } $where, $new_attrs->{where}
344 $new_attrs->{where} = (
345 defined $new_attrs->{where}
348 ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_
349 } $cond, $new_attrs->{where}
355 if (defined $having) {
356 $new_attrs->{having} = (
357 defined $new_attrs->{having}
360 ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_
361 } $having, $new_attrs->{having}
367 my $rs = (ref $self)->new($self->result_source, $new_attrs);
369 $rs->set_cache($rows);
374 =head2 search_literal
378 =item Arguments: $sql_fragment, @bind_values
380 =item Return Value: $resultset (scalar context), @row_objs (list context)
384 my @cds = $cd_rs->search_literal('year = ? AND title = ?', qw/2001 Reload/);
385 my $newrs = $artist_rs->search_literal('name = ?', 'Metallica');
387 Pass a literal chunk of SQL to be added to the conditional part of the
390 CAVEAT: C<search_literal> is provided for Class::DBI compatibility and should
391 only be used in that context. There are known problems using C<search_literal>
392 in chained queries; it can result in bind values in the wrong order. See
393 L<DBIx::Class::Manual::Cookbook/Searching> and
394 L<DBIx::Class::Manual::FAQ/Searching> for searching techniques that do not
395 require C<search_literal>.
400 my ($self, $cond, @vals) = @_;
401 my $attrs = (ref $vals[$#vals] eq 'HASH' ? { %{ pop(@vals) } } : {});
402 $attrs->{bind} = [ @{$self->{attrs}{bind}||[]}, @vals ];
403 return $self->search(\$cond, $attrs);
410 =item Arguments: @values | \%cols, \%attrs?
412 =item Return Value: $row_object | undef
416 Finds a row based on its primary key or unique constraint. For example, to find
417 a row by its primary key:
419 my $cd = $schema->resultset('CD')->find(5);
421 You can also find a row by a specific unique constraint using the C<key>
422 attribute. For example:
424 my $cd = $schema->resultset('CD')->find('Massive Attack', 'Mezzanine', {
425 key => 'cd_artist_title'
428 Additionally, you can specify the columns explicitly by name:
430 my $cd = $schema->resultset('CD')->find(
432 artist => 'Massive Attack',
433 title => 'Mezzanine',
435 { key => 'cd_artist_title' }
438 If the C<key> is specified as C<primary>, it searches only on the primary key.
440 If no C<key> is specified, it searches on all unique constraints defined on the
441 source for which column data is provided, including the primary key.
443 If your table does not have a primary key, you B<must> provide a value for the
444 C<key> attribute matching one of the unique constraints on the source.
446 In addition to C<key>, L</find> recognizes and applies standard
447 L<resultset attributes|/ATTRIBUTES> in the same way as L</search> does.
449 Note: If your query does not return only one row, a warning is generated:
451 Query returned more than one row
453 See also L</find_or_create> and L</update_or_create>. For information on how to
454 declare unique constraints, see
455 L<DBIx::Class::ResultSource/add_unique_constraint>.
461 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
463 # Default to the primary key, but allow a specific key
464 my @cols = exists $attrs->{key}
465 ? $self->result_source->unique_constraint_columns($attrs->{key})
466 : $self->result_source->primary_columns;
467 $self->throw_exception(
468 "Can't find unless a primary key is defined or unique constraint is specified"
471 # Parse out a hashref from input
473 if (ref $_[0] eq 'HASH') {
474 $input_query = { %{$_[0]} };
476 elsif (@_ == @cols) {
478 @{$input_query}{@cols} = @_;
481 # Compatibility: Allow e.g. find(id => $value)
482 carp "Find by key => value deprecated; please use a hashref instead";
486 my (%related, $info);
488 KEY: foreach my $key (keys %$input_query) {
489 if (ref($input_query->{$key})
490 && ($info = $self->result_source->relationship_info($key))) {
491 my $val = delete $input_query->{$key};
492 next KEY if (ref($val) eq 'ARRAY'); # has_many for multi_create
493 my $rel_q = $self->result_source->resolve_condition(
494 $info->{cond}, $val, $key
496 die "Can't handle OR join condition in find" if ref($rel_q) eq 'ARRAY';
497 @related{keys %$rel_q} = values %$rel_q;
500 if (my @keys = keys %related) {
501 @{$input_query}{@keys} = values %related;
505 # Build the final query: Default to the disjunction of the unique queries,
506 # but allow the input query in case the ResultSet defines the query or the
507 # user is abusing find
508 my $alias = exists $attrs->{alias} ? $attrs->{alias} : $self->{attrs}{alias};
510 if (exists $attrs->{key}) {
511 my @unique_cols = $self->result_source->unique_constraint_columns($attrs->{key});
512 my $unique_query = $self->_build_unique_query($input_query, \@unique_cols);
513 $query = $self->_add_alias($unique_query, $alias);
516 my @unique_queries = $self->_unique_queries($input_query, $attrs);
517 $query = @unique_queries
518 ? [ map { $self->_add_alias($_, $alias) } @unique_queries ]
519 : $self->_add_alias($input_query, $alias);
524 my $rs = $self->search($query, $attrs);
525 if (keys %{$rs->_resolved_attrs->{collapse}}) {
527 carp "Query returned more than one row" if $rs->next;
535 if (keys %{$self->_resolved_attrs->{collapse}}) {
536 my $rs = $self->search($query);
538 carp "Query returned more than one row" if $rs->next;
542 return $self->single($query);
549 # Add the specified alias to the specified query hash. A copy is made so the
550 # original query is not modified.
553 my ($self, $query, $alias) = @_;
555 my %aliased = %$query;
556 foreach my $col (grep { ! m/\./ } keys %aliased) {
557 $aliased{"$alias.$col"} = delete $aliased{$col};
565 # Build a list of queries which satisfy unique constraints.
567 sub _unique_queries {
568 my ($self, $query, $attrs) = @_;
570 my @constraint_names = exists $attrs->{key}
572 : $self->result_source->unique_constraint_names;
574 my $where = $self->_collapse_cond($self->{attrs}{where} || {});
575 my $num_where = scalar keys %$where;
578 foreach my $name (@constraint_names) {
579 my @unique_cols = $self->result_source->unique_constraint_columns($name);
580 my $unique_query = $self->_build_unique_query($query, \@unique_cols);
582 my $num_cols = scalar @unique_cols;
583 my $num_query = scalar keys %$unique_query;
585 my $total = $num_query + $num_where;
586 if ($num_query && ($num_query == $num_cols || $total == $num_cols)) {
587 # The query is either unique on its own or is unique in combination with
588 # the existing where clause
589 push @unique_queries, $unique_query;
593 return @unique_queries;
596 # _build_unique_query
598 # Constrain the specified query hash based on the specified column names.
600 sub _build_unique_query {
601 my ($self, $query, $unique_cols) = @_;
604 map { $_ => $query->{$_} }
605 grep { exists $query->{$_} }
610 =head2 search_related
614 =item Arguments: $rel, $cond, \%attrs?
616 =item Return Value: $new_resultset
620 $new_rs = $cd_rs->search_related('artist', {
624 Searches the specified relationship, optionally specifying a condition and
625 attributes for matching records. See L</ATTRIBUTES> for more information.
630 return shift->related_resultset(shift)->search(@_);
633 =head2 search_related_rs
635 This method works exactly the same as search_related, except that
636 it guarantees a restultset, even in list context.
640 sub search_related_rs {
641 return shift->related_resultset(shift)->search_rs(@_);
648 =item Arguments: none
650 =item Return Value: $cursor
654 Returns a storage-driven cursor to the given resultset. See
655 L<DBIx::Class::Cursor> for more information.
662 my $attrs = { %{$self->_resolved_attrs} };
663 return $self->{cursor}
664 ||= $self->result_source->storage->select($attrs->{from}, $attrs->{select},
665 $attrs->{where},$attrs);
672 =item Arguments: $cond?
674 =item Return Value: $row_object?
678 my $cd = $schema->resultset('CD')->single({ year => 2001 });
680 Inflates the first result without creating a cursor if the resultset has
681 any records in it; if not returns nothing. Used by L</find> as a lean version of
684 While this method can take an optional search condition (just like L</search>)
685 being a fast-code-path it does not recognize search attributes. If you need to
686 add extra joins or similar, call L</search> and then chain-call L</single> on the
687 L<DBIx::Class::ResultSet> returned.
693 As of 0.08100, this method enforces the assumption that the preceeding
694 query returns only one row. If more than one row is returned, you will receive
697 Query returned more than one row
699 In this case, you should be using L</first> or L</find> instead, or if you really
700 know what you are doing, use the L</rows> attribute to explicitly limit the size
708 my ($self, $where) = @_;
710 $self->throw_exception('single() only takes search conditions, no attributes. You want ->search( $cond, $attrs )->single()');
713 my $attrs = { %{$self->_resolved_attrs} };
715 if (defined $attrs->{where}) {
718 [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
719 $where, delete $attrs->{where} ]
722 $attrs->{where} = $where;
726 # XXX: Disabled since it doesn't infer uniqueness in all cases
727 # unless ($self->_is_unique_query($attrs->{where})) {
728 # carp "Query not guaranteed to return a single row"
729 # . "; please declare your unique constraints or use search instead";
732 my @data = $self->result_source->storage->select_single(
733 $attrs->{from}, $attrs->{select},
734 $attrs->{where}, $attrs
737 return (@data ? ($self->_construct_object(@data))[0] : undef);
742 # Try to determine if the specified query is guaranteed to be unique, based on
743 # the declared unique constraints.
745 sub _is_unique_query {
746 my ($self, $query) = @_;
748 my $collapsed = $self->_collapse_query($query);
749 my $alias = $self->{attrs}{alias};
751 foreach my $name ($self->result_source->unique_constraint_names) {
752 my @unique_cols = map {
754 } $self->result_source->unique_constraint_columns($name);
756 # Count the values for each unique column
757 my %seen = map { $_ => 0 } @unique_cols;
759 foreach my $key (keys %$collapsed) {
760 my $aliased = $key =~ /\./ ? $key : "$alias.$key";
761 next unless exists $seen{$aliased}; # Additional constraints are okay
762 $seen{$aliased} = scalar keys %{ $collapsed->{$key} };
765 # If we get 0 or more than 1 value for a column, it's not necessarily unique
766 return 1 unless grep { $_ != 1 } values %seen;
774 # Recursively collapse the query, accumulating values for each column.
776 sub _collapse_query {
777 my ($self, $query, $collapsed) = @_;
781 if (ref $query eq 'ARRAY') {
782 foreach my $subquery (@$query) {
783 next unless ref $subquery; # -or
784 # warn "ARRAY: " . Dumper $subquery;
785 $collapsed = $self->_collapse_query($subquery, $collapsed);
788 elsif (ref $query eq 'HASH') {
789 if (keys %$query and (keys %$query)[0] eq '-and') {
790 foreach my $subquery (@{$query->{-and}}) {
791 # warn "HASH: " . Dumper $subquery;
792 $collapsed = $self->_collapse_query($subquery, $collapsed);
796 # warn "LEAF: " . Dumper $query;
797 foreach my $col (keys %$query) {
798 my $value = $query->{$col};
799 $collapsed->{$col}{$value}++;
811 =item Arguments: $cond?
813 =item Return Value: $resultsetcolumn
817 my $max_length = $rs->get_column('length')->max;
819 Returns a L<DBIx::Class::ResultSetColumn> instance for a column of the ResultSet.
824 my ($self, $column) = @_;
825 my $new = DBIx::Class::ResultSetColumn->new($self, $column);
833 =item Arguments: $cond, \%attrs?
835 =item Return Value: $resultset (scalar context), @row_objs (list context)
839 # WHERE title LIKE '%blue%'
840 $cd_rs = $rs->search_like({ title => '%blue%'});
842 Performs a search, but uses C<LIKE> instead of C<=> as the condition. Note
843 that this is simply a convenience method retained for ex Class::DBI users.
844 You most likely want to use L</search> with specific operators.
846 For more information, see L<DBIx::Class::Manual::Cookbook>.
852 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
853 my $query = ref $_[0] eq 'HASH' ? { %{shift()} }: {@_};
854 $query->{$_} = { 'like' => $query->{$_} } for keys %$query;
855 return $class->search($query, { %$attrs });
862 =item Arguments: $first, $last
864 =item Return Value: $resultset (scalar context), @row_objs (list context)
868 Returns a resultset or object list representing a subset of elements from the
869 resultset slice is called on. Indexes are from 0, i.e., to get the first
872 my ($one, $two, $three) = $rs->slice(0, 2);
877 my ($self, $min, $max) = @_;
878 my $attrs = {}; # = { %{ $self->{attrs} || {} } };
879 $attrs->{offset} = $self->{attrs}{offset} || 0;
880 $attrs->{offset} += $min;
881 $attrs->{rows} = ($max ? ($max - $min + 1) : 1);
882 return $self->search(undef(), $attrs);
883 #my $slice = (ref $self)->new($self->result_source, $attrs);
884 #return (wantarray ? $slice->all : $slice);
891 =item Arguments: none
893 =item Return Value: $result?
897 Returns the next element in the resultset (C<undef> is there is none).
899 Can be used to efficiently iterate over records in the resultset:
901 my $rs = $schema->resultset('CD')->search;
902 while (my $cd = $rs->next) {
906 Note that you need to store the resultset object, and call C<next> on it.
907 Calling C<< resultset('Table')->next >> repeatedly will always return the
908 first record from the resultset.
914 if (my $cache = $self->get_cache) {
915 $self->{all_cache_position} ||= 0;
916 return $cache->[$self->{all_cache_position}++];
918 if ($self->{attrs}{cache}) {
919 $self->{all_cache_position} = 1;
920 return ($self->all)[0];
922 if ($self->{stashed_objects}) {
923 my $obj = shift(@{$self->{stashed_objects}});
924 delete $self->{stashed_objects} unless @{$self->{stashed_objects}};
928 exists $self->{stashed_row}
929 ? @{delete $self->{stashed_row}}
930 : $self->cursor->next
932 return undef unless (@row);
933 my ($row, @more) = $self->_construct_object(@row);
934 $self->{stashed_objects} = \@more if @more;
938 sub _construct_object {
939 my ($self, @row) = @_;
940 my $info = $self->_collapse_result($self->{_attrs}{as}, \@row);
941 my @new = $self->result_class->inflate_result($self->result_source, @$info);
942 @new = $self->{_attrs}{record_filter}->(@new)
943 if exists $self->{_attrs}{record_filter};
947 sub _collapse_result {
948 my ($self, $as_proto, $row) = @_;
952 # 'foo' => [ undef, 'foo' ]
953 # 'foo.bar' => [ 'foo', 'bar' ]
954 # 'foo.bar.baz' => [ 'foo.bar', 'baz' ]
956 my @construct_as = map { [ (/^(?:(.*)\.)?([^.]+)$/) ] } @$as_proto;
958 my %collapse = %{$self->{_attrs}{collapse}||{}};
962 # if we're doing collapsing (has_many prefetch) we need to grab records
963 # until the PK changes, so fill @pri_index. if not, we leave it empty so
964 # we know we don't have to bother.
966 # the reason for not using the collapse stuff directly is because if you
967 # had for e.g. two artists in a row with no cds, the collapse info for
968 # both would be NULL (undef) so you'd lose the second artist
970 # store just the index so we can check the array positions from the row
971 # without having to contruct the full hash
973 if (keys %collapse) {
974 my %pri = map { ($_ => 1) } $self->result_source->primary_columns;
975 foreach my $i (0 .. $#construct_as) {
976 next if defined($construct_as[$i][0]); # only self table
977 if (delete $pri{$construct_as[$i][1]}) {
978 push(@pri_index, $i);
980 last unless keys %pri; # short circuit (Johnny Five Is Alive!)
984 # no need to do an if, it'll be empty if @pri_index is empty anyway
986 my %pri_vals = map { ($_ => $copy[$_]) } @pri_index;
990 do { # no need to check anything at the front, we always want the first row
994 foreach my $this_as (@construct_as) {
995 $const{$this_as->[0]||''}{$this_as->[1]} = shift(@copy);
998 push(@const_rows, \%const);
1000 } until ( # no pri_index => no collapse => drop straight out
1003 do { # get another row, stash it, drop out if different PK
1005 @copy = $self->cursor->next;
1006 $self->{stashed_row} = \@copy;
1008 # last thing in do block, counts as true if anything doesn't match
1010 # check xor defined first for NULL vs. NOT NULL then if one is
1011 # defined the other must be so check string equality
1014 (defined $pri_vals{$_} ^ defined $copy[$_])
1015 || (defined $pri_vals{$_} && ($pri_vals{$_} ne $copy[$_]))
1020 my $alias = $self->{attrs}{alias};
1027 foreach my $const (@const_rows) {
1028 scalar @const_keys or do {
1029 @const_keys = sort { length($a) <=> length($b) } keys %$const;
1031 foreach my $key (@const_keys) {
1034 my @parts = split(/\./, $key);
1036 my $data = $const->{$key};
1037 foreach my $p (@parts) {
1038 $target = $target->[1]->{$p} ||= [];
1040 if ($cur eq ".${key}" && (my @ckey = @{$collapse{$cur}||[]})) {
1041 # collapsing at this point and on final part
1042 my $pos = $collapse_pos{$cur};
1043 CK: foreach my $ck (@ckey) {
1044 if (!defined $pos->{$ck} || $pos->{$ck} ne $data->{$ck}) {
1045 $collapse_pos{$cur} = $data;
1046 delete @collapse_pos{ # clear all positioning for sub-entries
1047 grep { m/^\Q${cur}.\E/ } keys %collapse_pos
1054 if (exists $collapse{$cur}) {
1055 $target = $target->[-1];
1058 $target->[0] = $data;
1060 $info->[0] = $const->{$key};
1068 =head2 result_source
1072 =item Arguments: $result_source?
1074 =item Return Value: $result_source
1078 An accessor for the primary ResultSource object from which this ResultSet
1085 =item Arguments: $result_class?
1087 =item Return Value: $result_class
1091 An accessor for the class to use when creating row objects. Defaults to
1092 C<< result_source->result_class >> - which in most cases is the name of the
1093 L<"table"|DBIx::Class::Manual::Glossary/"ResultSource"> class.
1098 my ($self, $result_class) = @_;
1099 if ($result_class) {
1100 $self->ensure_class_loaded($result_class);
1101 $self->_result_class($result_class);
1103 $self->_result_class;
1110 =item Arguments: $cond, \%attrs??
1112 =item Return Value: $count
1116 Performs an SQL C<COUNT> with the same query as the resultset was built
1117 with to find the number of elements. If passed arguments, does a search
1118 on the resultset and counts the results of that.
1120 Note: When using C<count> with C<group_by>, L<DBIx::Class> emulates C<GROUP BY>
1121 using C<COUNT( DISTINCT( columns ) )>. Some databases (notably SQLite) do
1122 not support C<DISTINCT> with multiple columns. If you are using such a
1123 database, you should only use columns from the main table in your C<group_by>
1130 return $self->search(@_)->count if @_ and defined $_[0];
1131 return scalar @{ $self->get_cache } if $self->get_cache;
1132 my $count = $self->_count;
1133 return 0 unless $count;
1135 # need to take offset from resolved attrs
1137 $count -= $self->{_attrs}{offset} if $self->{_attrs}{offset};
1138 $count = $self->{attrs}{rows} if
1139 $self->{attrs}{rows} and $self->{attrs}{rows} < $count;
1140 $count = 0 if ($count < 0);
1144 sub _count { # Separated out so pager can get the full count
1146 my $attrs = { %{$self->_resolved_attrs} };
1148 if (my $group_by = $attrs->{group_by}) {
1149 delete $attrs->{having};
1150 delete $attrs->{order_by};
1151 my @distinct = (ref $group_by ? @$group_by : ($group_by));
1152 # todo: try CONCAT for multi-column pk
1153 my @pk = $self->result_source->primary_columns;
1155 my $alias = $attrs->{alias};
1156 foreach my $column (@distinct) {
1157 if ($column =~ qr/^(?:\Q${alias}.\E)?$pk[0]$/) {
1158 @distinct = ($column);
1164 $attrs->{select} = $group_by;
1165 $attrs->{from} = [ { 'mesub' => (ref $self)->new($self->result_source, $attrs)->cursor->as_query } ];
1166 delete $attrs->{where};
1169 $attrs->{select} = { count => '*' };
1170 $attrs->{as} = [qw/count/];
1172 # offset, order by, group by, where and page are not needed to count. record_filter is cdbi
1173 delete $attrs->{$_} for qw/rows offset order_by group_by page pager record_filter/;
1175 my $tmp_rs = (ref $self)->new($self->result_source, $attrs);
1176 my ($count) = $tmp_rs->cursor->next;
1184 =head2 count_literal
1188 =item Arguments: $sql_fragment, @bind_values
1190 =item Return Value: $count
1194 Counts the results in a literal query. Equivalent to calling L</search_literal>
1195 with the passed arguments, then L</count>.
1199 sub count_literal { shift->search_literal(@_)->count; }
1205 =item Arguments: none
1207 =item Return Value: @objects
1211 Returns all elements in the resultset. Called implicitly if the resultset
1212 is returned in list context.
1219 $self->throw_exception("all() doesn't take any arguments, you probably wanted ->search(...)->all()");
1222 return @{ $self->get_cache } if $self->get_cache;
1226 # TODO: don't call resolve here
1227 if (keys %{$self->_resolved_attrs->{collapse}}) {
1228 # if ($self->{attrs}{prefetch}) {
1229 # Using $self->cursor->all is really just an optimisation.
1230 # If we're collapsing has_many prefetches it probably makes
1231 # very little difference, and this is cleaner than hacking
1232 # _construct_object to survive the approach
1233 my @row = $self->cursor->next;
1235 push(@obj, $self->_construct_object(@row));
1236 @row = (exists $self->{stashed_row}
1237 ? @{delete $self->{stashed_row}}
1238 : $self->cursor->next);
1241 @obj = map { $self->_construct_object(@$_) } $self->cursor->all;
1244 $self->set_cache(\@obj) if $self->{attrs}{cache};
1252 =item Arguments: none
1254 =item Return Value: $self
1258 Resets the resultset's cursor, so you can iterate through the elements again.
1264 delete $self->{_attrs} if exists $self->{_attrs};
1265 $self->{all_cache_position} = 0;
1266 $self->cursor->reset;
1274 =item Arguments: none
1276 =item Return Value: $object?
1280 Resets the resultset and returns an object for the first result (if the
1281 resultset returns anything).
1286 return $_[0]->reset->next;
1289 # _cond_for_update_delete
1291 # update/delete require the condition to be modified to handle
1292 # the differing SQL syntax available. This transforms the $self->{cond}
1293 # appropriately, returning the new condition.
1295 sub _cond_for_update_delete {
1296 my ($self, $full_cond) = @_;
1299 $full_cond ||= $self->{cond};
1300 # No-op. No condition, we're updating/deleting everything
1301 return $cond unless ref $full_cond;
1303 if (ref $full_cond eq 'ARRAY') {
1307 foreach my $key (keys %{$_}) {
1309 $hash{$1} = $_->{$key};
1315 elsif (ref $full_cond eq 'HASH') {
1316 if ((keys %{$full_cond})[0] eq '-and') {
1319 my @cond = @{$full_cond->{-and}};
1320 for (my $i = 0; $i < @cond; $i++) {
1321 my $entry = $cond[$i];
1324 if (ref $entry eq 'HASH') {
1325 $hash = $self->_cond_for_update_delete($entry);
1328 $entry =~ /([^.]+)$/;
1329 $hash->{$1} = $cond[++$i];
1332 push @{$cond->{-and}}, $hash;
1336 foreach my $key (keys %{$full_cond}) {
1338 $cond->{$1} = $full_cond->{$key};
1343 $self->throw_exception(
1344 "Can't update/delete on resultset with condition unless hash or array"
1356 =item Arguments: \%values
1358 =item Return Value: $storage_rv
1362 Sets the specified columns in the resultset to the supplied values in a
1363 single query. Return value will be true if the update succeeded or false
1364 if no records were updated; exact type of success value is storage-dependent.
1369 my ($self, $values) = @_;
1370 $self->throw_exception("Values for update must be a hash")
1371 unless ref $values eq 'HASH';
1373 carp( 'WARNING! Currently $rs->update() does not generate proper SQL'
1374 . ' on joined resultsets, and may affect rows well outside of the'
1375 . ' contents of $rs. Use at your own risk' )
1376 if ( $self->{attrs}{seen_join} );
1378 my $cond = $self->_cond_for_update_delete;
1380 return $self->result_source->storage->update(
1381 $self->result_source, $values, $cond
1389 =item Arguments: \%values
1391 =item Return Value: 1
1395 Fetches all objects and updates them one at a time. Note that C<update_all>
1396 will run DBIC cascade triggers, while L</update> will not.
1401 my ($self, $values) = @_;
1402 $self->throw_exception("Values for update must be a hash")
1403 unless ref $values eq 'HASH';
1404 foreach my $obj ($self->all) {
1405 $obj->set_columns($values)->update;
1414 =item Arguments: none
1416 =item Return Value: 1
1420 Deletes the contents of the resultset from its result source. Note that this
1421 will not run DBIC cascade triggers. See L</delete_all> if you need triggers
1422 to run. See also L<DBIx::Class::Row/delete>.
1424 delete may not generate correct SQL for a query with joins or a resultset
1425 chained from a related resultset. In this case it will generate a warning:-
1427 WARNING! Currently $rs->delete() does not generate proper SQL on
1428 joined resultsets, and may delete rows well outside of the contents
1429 of $rs. Use at your own risk
1431 In these cases you may find that delete_all is more appropriate, or you
1432 need to respecify your query in a way that can be expressed without a join.
1438 $self->throw_exception("Delete should not be passed any arguments")
1440 carp( 'WARNING! Currently $rs->delete() does not generate proper SQL'
1441 . ' on joined resultsets, and may delete rows well outside of the'
1442 . ' contents of $rs. Use at your own risk' )
1443 if ( $self->{attrs}{seen_join} );
1444 my $cond = $self->_cond_for_update_delete;
1446 $self->result_source->storage->delete($self->result_source, $cond);
1454 =item Arguments: none
1456 =item Return Value: 1
1460 Fetches all objects and deletes them one at a time. Note that C<delete_all>
1461 will run DBIC cascade triggers, while L</delete> will not.
1467 $_->delete for $self->all;
1475 =item Arguments: \@data;
1479 Accepts either an arrayref of hashrefs or alternatively an arrayref of arrayrefs.
1480 For the arrayref of hashrefs style each hashref should be a structure suitable
1481 forsubmitting to a $resultset->create(...) method.
1483 In void context, C<insert_bulk> in L<DBIx::Class::Storage::DBI> is used
1484 to insert the data, as this is a faster method.
1486 Otherwise, each set of data is inserted into the database using
1487 L<DBIx::Class::ResultSet/create>, and a arrayref of the resulting row
1488 objects is returned.
1490 Example: Assuming an Artist Class that has many CDs Classes relating:
1492 my $Artist_rs = $schema->resultset("Artist");
1494 ## Void Context Example
1495 $Artist_rs->populate([
1496 { artistid => 4, name => 'Manufactured Crap', cds => [
1497 { title => 'My First CD', year => 2006 },
1498 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
1501 { artistid => 5, name => 'Angsty-Whiny Girl', cds => [
1502 { title => 'My parents sold me to a record company' ,year => 2005 },
1503 { title => 'Why Am I So Ugly?', year => 2006 },
1504 { title => 'I Got Surgery and am now Popular', year => 2007 }
1509 ## Array Context Example
1510 my ($ArtistOne, $ArtistTwo, $ArtistThree) = $Artist_rs->populate([
1511 { name => "Artist One"},
1512 { name => "Artist Two"},
1513 { name => "Artist Three", cds=> [
1514 { title => "First CD", year => 2007},
1515 { title => "Second CD", year => 2008},
1519 print $ArtistOne->name; ## response is 'Artist One'
1520 print $ArtistThree->cds->count ## reponse is '2'
1522 For the arrayref of arrayrefs style, the first element should be a list of the
1523 fieldsnames to which the remaining elements are rows being inserted. For
1526 $Arstist_rs->populate([
1527 [qw/artistid name/],
1528 [100, 'A Formally Unknown Singer'],
1529 [101, 'A singer that jumped the shark two albums ago'],
1530 [102, 'An actually cool singer.'],
1533 Please note an important effect on your data when choosing between void and
1534 wantarray context. Since void context goes straight to C<insert_bulk> in
1535 L<DBIx::Class::Storage::DBI> this will skip any component that is overriding
1536 c<insert>. So if you are using something like L<DBIx-Class-UUIDColumns> to
1537 create primary keys for you, you will find that your PKs are empty. In this
1538 case you will have to use the wantarray context in order to create those
1544 my $self = shift @_;
1545 my $data = ref $_[0][0] eq 'HASH'
1546 ? $_[0] : ref $_[0][0] eq 'ARRAY' ? $self->_normalize_populate_args($_[0]) :
1547 $self->throw_exception('Populate expects an arrayref of hashes or arrayref of arrayrefs');
1549 if(defined wantarray) {
1551 foreach my $item (@$data) {
1552 push(@created, $self->create($item));
1556 my ($first, @rest) = @$data;
1558 my @names = grep {!ref $first->{$_}} keys %$first;
1559 my @rels = grep { $self->result_source->has_relationship($_) } keys %$first;
1560 my @pks = $self->result_source->primary_columns;
1562 ## do the belongs_to relationships
1563 foreach my $index (0..$#$data) {
1564 if( grep { !defined $data->[$index]->{$_} } @pks ) {
1565 my @ret = $self->populate($data);
1569 foreach my $rel (@rels) {
1570 next unless $data->[$index]->{$rel} && ref $data->[$index]->{$rel} eq "HASH";
1571 my $result = $self->related_resultset($rel)->create($data->[$index]->{$rel});
1572 my ($reverse) = keys %{$self->result_source->reverse_relationship_info($rel)};
1573 my $related = $result->result_source->resolve_condition(
1574 $result->result_source->relationship_info($reverse)->{cond},
1579 delete $data->[$index]->{$rel};
1580 $data->[$index] = {%{$data->[$index]}, %$related};
1582 push @names, keys %$related if $index == 0;
1586 ## do bulk insert on current row
1587 my @values = map { [ @$_{@names} ] } @$data;
1589 $self->result_source->storage->insert_bulk(
1590 $self->result_source,
1595 ## do the has_many relationships
1596 foreach my $item (@$data) {
1598 foreach my $rel (@rels) {
1599 next unless $item->{$rel} && ref $item->{$rel} eq "ARRAY";
1601 my $parent = $self->find(map {{$_=>$item->{$_}} } @pks)
1602 || $self->throw_exception('Cannot find the relating object.');
1604 my $child = $parent->$rel;
1606 my $related = $child->result_source->resolve_condition(
1607 $parent->result_source->relationship_info($rel)->{cond},
1612 my @rows_to_add = ref $item->{$rel} eq 'ARRAY' ? @{$item->{$rel}} : ($item->{$rel});
1613 my @populate = map { {%$_, %$related} } @rows_to_add;
1615 $child->populate( \@populate );
1621 =head2 _normalize_populate_args ($args)
1623 Private method used by L</populate> to normalize its incoming arguments. Factored
1624 out in case you want to subclass and accept new argument structures to the
1625 L</populate> method.
1629 sub _normalize_populate_args {
1630 my ($self, $data) = @_;
1631 my @names = @{shift(@$data)};
1632 my @results_to_create;
1633 foreach my $datum (@$data) {
1634 my %result_to_create;
1635 foreach my $index (0..$#names) {
1636 $result_to_create{$names[$index]} = $$datum[$index];
1638 push @results_to_create, \%result_to_create;
1640 return \@results_to_create;
1647 =item Arguments: none
1649 =item Return Value: $pager
1653 Return Value a L<Data::Page> object for the current resultset. Only makes
1654 sense for queries with a C<page> attribute.
1656 To get the full count of entries for a paged resultset, call
1657 C<total_entries> on the L<Data::Page> object.
1663 my $attrs = $self->{attrs};
1664 $self->throw_exception("Can't create pager for non-paged rs")
1665 unless $self->{attrs}{page};
1666 $attrs->{rows} ||= 10;
1667 return $self->{pager} ||= Data::Page->new(
1668 $self->_count, $attrs->{rows}, $self->{attrs}{page});
1675 =item Arguments: $page_number
1677 =item Return Value: $rs
1681 Returns a resultset for the $page_number page of the resultset on which page
1682 is called, where each page contains a number of rows equal to the 'rows'
1683 attribute set on the resultset (10 by default).
1688 my ($self, $page) = @_;
1689 return (ref $self)->new($self->result_source, { %{$self->{attrs}}, page => $page });
1696 =item Arguments: \%vals
1698 =item Return Value: $rowobject
1702 Creates a new row object in the resultset's result class and returns
1703 it. The row is not inserted into the database at this point, call
1704 L<DBIx::Class::Row/insert> to do that. Calling L<DBIx::Class::Row/in_storage>
1705 will tell you whether the row object has been inserted or not.
1707 Passes the hashref of input on to L<DBIx::Class::Row/new>.
1712 my ($self, $values) = @_;
1713 $self->throw_exception( "new_result needs a hash" )
1714 unless (ref $values eq 'HASH');
1717 my $alias = $self->{attrs}{alias};
1720 defined $self->{cond}
1721 && $self->{cond} eq $DBIx::Class::ResultSource::UNRESOLVABLE_CONDITION
1723 %new = %{ $self->{attrs}{related_objects} || {} }; # nothing might have been inserted yet
1724 $new{-from_resultset} = [ keys %new ] if keys %new;
1726 $self->throw_exception(
1727 "Can't abstract implicit construct, condition not a hash"
1728 ) if ($self->{cond} && !(ref $self->{cond} eq 'HASH'));
1730 my $collapsed_cond = (
1732 ? $self->_collapse_cond($self->{cond})
1736 # precendence must be given to passed values over values inherited from
1737 # the cond, so the order here is important.
1738 my %implied = %{$self->_remove_alias($collapsed_cond, $alias)};
1739 while( my($col,$value) = each %implied ){
1740 if(ref($value) eq 'HASH' && keys(%$value) && (keys %$value)[0] eq '='){
1741 $new{$col} = $value->{'='};
1744 $new{$col} = $value if $self->_is_deterministic_value($value);
1750 %{ $self->_remove_alias($values, $alias) },
1751 -source_handle => $self->_source_handle,
1752 -result_source => $self->result_source, # DO NOT REMOVE THIS, REQUIRED
1755 return $self->result_class->new(\%new);
1758 # _is_deterministic_value
1760 # Make an effor to strip non-deterministic values from the condition,
1761 # to make sure new_result chokes less
1763 sub _is_deterministic_value {
1766 my $ref_type = ref $value;
1767 return 1 if $ref_type eq '' || $ref_type eq 'SCALAR';
1768 return 1 if Scalar::Util::blessed($value);
1774 # Recursively collapse the condition.
1776 sub _collapse_cond {
1777 my ($self, $cond, $collapsed) = @_;
1781 if (ref $cond eq 'ARRAY') {
1782 foreach my $subcond (@$cond) {
1783 next unless ref $subcond; # -or
1784 # warn "ARRAY: " . Dumper $subcond;
1785 $collapsed = $self->_collapse_cond($subcond, $collapsed);
1788 elsif (ref $cond eq 'HASH') {
1789 if (keys %$cond and (keys %$cond)[0] eq '-and') {
1790 foreach my $subcond (@{$cond->{-and}}) {
1791 # warn "HASH: " . Dumper $subcond;
1792 $collapsed = $self->_collapse_cond($subcond, $collapsed);
1796 # warn "LEAF: " . Dumper $cond;
1797 foreach my $col (keys %$cond) {
1798 my $value = $cond->{$col};
1799 $collapsed->{$col} = $value;
1809 # Remove the specified alias from the specified query hash. A copy is made so
1810 # the original query is not modified.
1813 my ($self, $query, $alias) = @_;
1815 my %orig = %{ $query || {} };
1818 foreach my $key (keys %orig) {
1820 $unaliased{$key} = $orig{$key};
1823 $unaliased{$1} = $orig{$key}
1824 if $key =~ m/^(?:\Q$alias\E\.)?([^.]+)$/;
1830 =head2 as_query (EXPERIMENTAL)
1834 =item Arguments: none
1836 =item Return Value: \[ $sql, @bind ]
1840 Returns the SQL query and bind vars associated with the invocant.
1842 This is generally used as the RHS for a subquery.
1844 B<NOTE>: This feature is still experimental.
1848 sub as_query { return shift->cursor->as_query(@_) }
1854 =item Arguments: \%vals, \%attrs?
1856 =item Return Value: $rowobject
1860 my $artist = $schema->resultset('Artist')->find_or_new(
1861 { artist => 'fred' }, { key => 'artists' });
1863 $cd->cd_to_producer->find_or_new({ producer => $producer },
1864 { key => 'primary });
1866 Find an existing record from this resultset, based on its primary
1867 key, or a unique constraint. If none exists, instantiate a new result
1868 object and return it. The object will not be saved into your storage
1869 until you call L<DBIx::Class::Row/insert> on it.
1871 You most likely want this method when looking for existing rows using
1872 a unique constraint that is not the primary key, or looking for
1875 If you want objects to be saved immediately, use L</find_or_create> instead.
1877 B<Note>: C<find_or_new> is probably not what you want when creating a
1878 new row in a table that uses primary keys supplied by the
1879 database. Passing in a primary key column with a value of I<undef>
1880 will cause L</find> to attempt to search for a row with a value of
1887 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1888 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
1889 my $exists = $self->find($hash, $attrs);
1890 return defined $exists ? $exists : $self->new_result($hash);
1897 =item Arguments: \%vals
1899 =item Return Value: a L<DBIx::Class::Row> $object
1903 Attempt to create a single new row or a row with multiple related rows
1904 in the table represented by the resultset (and related tables). This
1905 will not check for duplicate rows before inserting, use
1906 L</find_or_create> to do that.
1908 To create one row for this resultset, pass a hashref of key/value
1909 pairs representing the columns of the table and the values you wish to
1910 store. If the appropriate relationships are set up, foreign key fields
1911 can also be passed an object representing the foreign row, and the
1912 value will be set to its primary key.
1914 To create related objects, pass a hashref for the value if the related
1915 item is a foreign key relationship (L<DBIx::Class::Relationship/belongs_to>),
1916 and use the name of the relationship as the key. (NOT the name of the field,
1917 necessarily). For C<has_many> and C<has_one> relationships, pass an arrayref
1918 of hashrefs containing the data for each of the rows to create in the foreign
1919 tables, again using the relationship name as the key.
1921 Instead of hashrefs of plain related data (key/value pairs), you may
1922 also pass new or inserted objects. New objects (not inserted yet, see
1923 L</new>), will be inserted into their appropriate tables.
1925 Effectively a shortcut for C<< ->new_result(\%vals)->insert >>.
1927 Example of creating a new row.
1929 $person_rs->create({
1930 name=>"Some Person",
1931 email=>"somebody@someplace.com"
1934 Example of creating a new row and also creating rows in a related C<has_many>
1935 or C<has_one> resultset. Note Arrayref.
1938 { artistid => 4, name => 'Manufactured Crap', cds => [
1939 { title => 'My First CD', year => 2006 },
1940 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
1945 Example of creating a new row and also creating a row in a related
1946 C<belongs_to>resultset. Note Hashref.
1949 title=>"Music for Silly Walks",
1952 name=>"Silly Musician",
1959 my ($self, $attrs) = @_;
1960 $self->throw_exception( "create needs a hashref" )
1961 unless ref $attrs eq 'HASH';
1962 return $self->new_result($attrs)->insert;
1965 =head2 find_or_create
1969 =item Arguments: \%vals, \%attrs?
1971 =item Return Value: $rowobject
1975 $cd->cd_to_producer->find_or_create({ producer => $producer },
1976 { key => 'primary });
1978 Tries to find a record based on its primary key or unique constraints; if none
1979 is found, creates one and returns that instead.
1981 my $cd = $schema->resultset('CD')->find_or_create({
1983 artist => 'Massive Attack',
1984 title => 'Mezzanine',
1988 Also takes an optional C<key> attribute, to search by a specific key or unique
1989 constraint. For example:
1991 my $cd = $schema->resultset('CD')->find_or_create(
1993 artist => 'Massive Attack',
1994 title => 'Mezzanine',
1996 { key => 'cd_artist_title' }
1999 B<Note>: Because find_or_create() reads from the database and then
2000 possibly inserts based on the result, this method is subject to a race
2001 condition. Another process could create a record in the table after
2002 the find has completed and before the create has started. To avoid
2003 this problem, use find_or_create() inside a transaction.
2005 B<Note>: C<find_or_create> is probably not what you want when creating
2006 a new row in a table that uses primary keys supplied by the
2007 database. Passing in a primary key column with a value of I<undef>
2008 will cause L</find> to attempt to search for a row with a value of
2011 See also L</find> and L</update_or_create>. For information on how to declare
2012 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2016 sub find_or_create {
2018 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2019 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2020 my $exists = $self->find($hash, $attrs);
2021 return defined $exists ? $exists : $self->create($hash);
2024 =head2 update_or_create
2028 =item Arguments: \%col_values, { key => $unique_constraint }?
2030 =item Return Value: $rowobject
2034 $resultset->update_or_create({ col => $val, ... });
2036 First, searches for an existing row matching one of the unique constraints
2037 (including the primary key) on the source of this resultset. If a row is
2038 found, updates it with the other given column values. Otherwise, creates a new
2041 Takes an optional C<key> attribute to search on a specific unique constraint.
2044 # In your application
2045 my $cd = $schema->resultset('CD')->update_or_create(
2047 artist => 'Massive Attack',
2048 title => 'Mezzanine',
2051 { key => 'cd_artist_title' }
2054 $cd->cd_to_producer->update_or_create({
2055 producer => $producer,
2062 If no C<key> is specified, it searches on all unique constraints defined on the
2063 source, including the primary key.
2065 If the C<key> is specified as C<primary>, it searches only on the primary key.
2067 See also L</find> and L</find_or_create>. For information on how to declare
2068 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2070 B<Note>: C<update_or_create> is probably not what you want when
2071 looking for a row in a table that uses primary keys supplied by the
2072 database, unless you actually have a key value. Passing in a primary
2073 key column with a value of I<undef> will cause L</find> to attempt to
2074 search for a row with a value of I<NULL>.
2078 sub update_or_create {
2080 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2081 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
2083 my $row = $self->find($cond, $attrs);
2085 $row->update($cond);
2089 return $self->create($cond);
2096 =item Arguments: none
2098 =item Return Value: \@cache_objects?
2102 Gets the contents of the cache for the resultset, if the cache is set.
2104 The cache is populated either by using the L</prefetch> attribute to
2105 L</search> or by calling L</set_cache>.
2117 =item Arguments: \@cache_objects
2119 =item Return Value: \@cache_objects
2123 Sets the contents of the cache for the resultset. Expects an arrayref
2124 of objects of the same class as those produced by the resultset. Note that
2125 if the cache is set the resultset will return the cached objects rather
2126 than re-querying the database even if the cache attr is not set.
2128 The contents of the cache can also be populated by using the
2129 L</prefetch> attribute to L</search>.
2134 my ( $self, $data ) = @_;
2135 $self->throw_exception("set_cache requires an arrayref")
2136 if defined($data) && (ref $data ne 'ARRAY');
2137 $self->{all_cache} = $data;
2144 =item Arguments: none
2146 =item Return Value: []
2150 Clears the cache for the resultset.
2155 shift->set_cache(undef);
2158 =head2 related_resultset
2162 =item Arguments: $relationship_name
2164 =item Return Value: $resultset
2168 Returns a related resultset for the supplied relationship name.
2170 $artist_rs = $schema->resultset('CD')->related_resultset('Artist');
2174 sub related_resultset {
2175 my ($self, $rel) = @_;
2177 $self->{related_resultsets} ||= {};
2178 return $self->{related_resultsets}{$rel} ||= do {
2179 my $rel_obj = $self->result_source->relationship_info($rel);
2181 $self->throw_exception(
2182 "search_related: result source '" . $self->result_source->source_name .
2183 "' has no such relationship $rel")
2186 my ($from,$seen) = $self->_resolve_from($rel);
2188 my $join_count = $seen->{$rel};
2189 my $alias = ($join_count > 1 ? join('_', $rel, $join_count) : $rel);
2191 #XXX - temp fix for result_class bug. There likely is a more elegant fix -groditi
2192 my %attrs = %{$self->{attrs}||{}};
2193 delete @attrs{qw(result_class alias)};
2197 if (my $cache = $self->get_cache) {
2198 if ($cache->[0] && $cache->[0]->related_resultset($rel)->get_cache) {
2199 $new_cache = [ map { @{$_->related_resultset($rel)->get_cache} }
2204 my $rel_source = $self->result_source->related_source($rel);
2208 # The reason we do this now instead of passing the alias to the
2209 # search_rs below is that if you wrap/overload resultset on the
2210 # source you need to know what alias it's -going- to have for things
2211 # to work sanely (e.g. RestrictWithObject wants to be able to add
2212 # extra query restrictions, and these may need to be $alias.)
2214 my $attrs = $rel_source->resultset_attributes;
2215 local $attrs->{alias} = $alias;
2217 $rel_source->resultset
2225 where => $self->{cond},
2230 $new->set_cache($new_cache) if $new_cache;
2235 =head2 current_source_alias
2239 =item Arguments: none
2241 =item Return Value: $source_alias
2245 Returns the current table alias for the result source this resultset is built
2246 on, that will be used in the SQL query. Usually it is C<me>.
2248 Currently the source alias that refers to the result set returned by a
2249 L</search>/L</find> family method depends on how you got to the resultset: it's
2250 C<me> by default, but eg. L</search_related> aliases it to the related result
2251 source name (and keeps C<me> referring to the original result set). The long
2252 term goal is to make L<DBIx::Class> always alias the current resultset as C<me>
2253 (and make this method unnecessary).
2255 Thus it's currently necessary to use this method in predefined queries (see
2256 L<DBIx::Class::Manual::Cookbook/Predefined searches>) when referring to the
2257 source alias of the current result set:
2259 # in a result set class
2261 my ($self, $user) = @_;
2263 my $me = $self->current_source_alias;
2265 return $self->search(
2266 "$me.modified" => $user->id,
2272 sub current_source_alias {
2275 return ($self->{attrs} || {})->{alias} || 'me';
2279 my ($self, $extra_join) = @_;
2280 my $source = $self->result_source;
2281 my $attrs = $self->{attrs};
2283 my $from = $attrs->{from}
2284 || [ { $attrs->{alias} => $source->from } ];
2286 my $seen = { %{$attrs->{seen_join}||{}} };
2288 my $join = ($attrs->{join}
2289 ? [ $attrs->{join}, $extra_join ]
2292 # we need to take the prefetch the attrs into account before we
2293 # ->resolve_join as otherwise they get lost - captainL
2294 my $merged = $self->_merge_attr( $join, $attrs->{prefetch} );
2298 ($join ? $source->resolve_join($merged, $attrs->{alias}, $seen) : ()),
2301 return ($from,$seen);
2304 sub _resolved_attrs {
2306 return $self->{_attrs} if $self->{_attrs};
2308 my $attrs = { %{ $self->{attrs} || {} } };
2309 my $source = $self->result_source;
2310 my $alias = $attrs->{alias};
2312 $attrs->{columns} ||= delete $attrs->{cols} if exists $attrs->{cols};
2315 # build columns (as long as select isn't set) into a set of as/select hashes
2316 unless ( $attrs->{select} ) {
2318 ( ref($_) eq 'HASH' ) ? $_
2321 /^\Q${alias}.\E(.+)$/ ? $1
2323 ) => ( /\./ ? $_ : "${alias}.$_" )
2325 } ( ref($attrs->{columns}) eq 'ARRAY' ) ? @{ delete $attrs->{columns}} : (delete $attrs->{columns} || $source->columns );
2327 # add the additional columns on
2328 foreach ( 'include_columns', '+columns' ) {
2329 push @colbits, map {
2330 ( ref($_) eq 'HASH' )
2332 : { ( split( /\./, $_ ) )[-1] => ( /\./ ? $_ : "${alias}.$_" ) }
2333 } ( ref($attrs->{$_}) eq 'ARRAY' ) ? @{ delete $attrs->{$_} } : delete $attrs->{$_} if ( $attrs->{$_} );
2336 # start with initial select items
2337 if ( $attrs->{select} ) {
2339 ( ref $attrs->{select} eq 'ARRAY' )
2340 ? [ @{ $attrs->{select} } ]
2341 : [ $attrs->{select} ];
2345 ref $attrs->{as} eq 'ARRAY'
2346 ? [ @{ $attrs->{as} } ]
2349 : [ map { m/^\Q${alias}.\E(.+)$/ ? $1 : $_ } @{ $attrs->{select} } ]
2354 # otherwise we intialise select & as to empty
2355 $attrs->{select} = [];
2359 # now add colbits to select/as
2360 push( @{ $attrs->{select} }, map { values( %{$_} ) } @colbits );
2361 push( @{ $attrs->{as} }, map { keys( %{$_} ) } @colbits );
2364 if ( $adds = delete $attrs->{'+select'} ) {
2365 $adds = [$adds] unless ref $adds eq 'ARRAY';
2367 @{ $attrs->{select} },
2368 map { /\./ || ref $_ ? $_ : "${alias}.$_" } @$adds
2371 if ( $adds = delete $attrs->{'+as'} ) {
2372 $adds = [$adds] unless ref $adds eq 'ARRAY';
2373 push( @{ $attrs->{as} }, @$adds );
2376 $attrs->{from} ||= [ { $self->{attrs}{alias} => $source->from } ];
2378 if ( exists $attrs->{join} || exists $attrs->{prefetch} ) {
2379 my $join = delete $attrs->{join} || {};
2381 if ( defined $attrs->{prefetch} ) {
2382 $join = $self->_merge_attr( $join, $attrs->{prefetch} );
2386 $attrs->{from} = # have to copy here to avoid corrupting the original
2388 @{ $attrs->{from} },
2389 $source->resolve_join(
2390 $join, $alias, { %{ $attrs->{seen_join} || {} } }
2396 $attrs->{group_by} ||= $attrs->{select}
2397 if delete $attrs->{distinct};
2398 if ( $attrs->{order_by} ) {
2399 $attrs->{order_by} = (
2400 ref( $attrs->{order_by} ) eq 'ARRAY'
2401 ? [ @{ $attrs->{order_by} } ]
2402 : [ $attrs->{order_by} ]
2406 $attrs->{order_by} = [];
2409 my $collapse = $attrs->{collapse} || {};
2410 if ( my $prefetch = delete $attrs->{prefetch} ) {
2411 $prefetch = $self->_merge_attr( {}, $prefetch );
2413 my $seen = { %{ $attrs->{seen_join} || {} } };
2414 foreach my $p ( ref $prefetch eq 'ARRAY' ? @$prefetch : ($prefetch) ) {
2416 # bring joins back to level of current class
2418 $source->resolve_prefetch( $p, $alias, $seen, \@pre_order, $collapse );
2419 push( @{ $attrs->{select} }, map { $_->[0] } @prefetch );
2420 push( @{ $attrs->{as} }, map { $_->[1] } @prefetch );
2422 push( @{ $attrs->{order_by} }, @pre_order );
2424 $attrs->{collapse} = $collapse;
2426 if ( $attrs->{page} ) {
2427 $attrs->{offset} ||= 0;
2428 $attrs->{offset} += ( $attrs->{rows} * ( $attrs->{page} - 1 ) );
2431 return $self->{_attrs} = $attrs;
2435 my ($self, $attr) = @_;
2437 if (ref $attr eq 'HASH') {
2438 return $self->_rollout_hash($attr);
2439 } elsif (ref $attr eq 'ARRAY') {
2440 return $self->_rollout_array($attr);
2446 sub _rollout_array {
2447 my ($self, $attr) = @_;
2450 foreach my $element (@{$attr}) {
2451 if (ref $element eq 'HASH') {
2452 push( @rolled_array, @{ $self->_rollout_hash( $element ) } );
2453 } elsif (ref $element eq 'ARRAY') {
2454 # XXX - should probably recurse here
2455 push( @rolled_array, @{$self->_rollout_array($element)} );
2457 push( @rolled_array, $element );
2460 return \@rolled_array;
2464 my ($self, $attr) = @_;
2467 foreach my $key (keys %{$attr}) {
2468 push( @rolled_array, { $key => $attr->{$key} } );
2470 return \@rolled_array;
2473 sub _calculate_score {
2474 my ($self, $a, $b) = @_;
2476 if (ref $b eq 'HASH') {
2477 my ($b_key) = keys %{$b};
2478 if (ref $a eq 'HASH') {
2479 my ($a_key) = keys %{$a};
2480 if ($a_key eq $b_key) {
2481 return (1 + $self->_calculate_score( $a->{$a_key}, $b->{$b_key} ));
2486 return ($a eq $b_key) ? 1 : 0;
2489 if (ref $a eq 'HASH') {
2490 my ($a_key) = keys %{$a};
2491 return ($b eq $a_key) ? 1 : 0;
2493 return ($b eq $a) ? 1 : 0;
2499 my ($self, $orig, $import) = @_;
2501 return $import unless defined($orig);
2502 return $orig unless defined($import);
2504 $orig = $self->_rollout_attr($orig);
2505 $import = $self->_rollout_attr($import);
2508 foreach my $import_element ( @{$import} ) {
2509 # find best candidate from $orig to merge $b_element into
2510 my $best_candidate = { position => undef, score => 0 }; my $position = 0;
2511 foreach my $orig_element ( @{$orig} ) {
2512 my $score = $self->_calculate_score( $orig_element, $import_element );
2513 if ($score > $best_candidate->{score}) {
2514 $best_candidate->{position} = $position;
2515 $best_candidate->{score} = $score;
2519 my ($import_key) = ( ref $import_element eq 'HASH' ) ? keys %{$import_element} : ($import_element);
2521 if ($best_candidate->{score} == 0 || exists $seen_keys->{$import_key}) {
2522 push( @{$orig}, $import_element );
2524 my $orig_best = $orig->[$best_candidate->{position}];
2525 # merge orig_best and b_element together and replace original with merged
2526 if (ref $orig_best ne 'HASH') {
2527 $orig->[$best_candidate->{position}] = $import_element;
2528 } elsif (ref $import_element eq 'HASH') {
2529 my ($key) = keys %{$orig_best};
2530 $orig->[$best_candidate->{position}] = { $key => $self->_merge_attr($orig_best->{$key}, $import_element->{$key}) };
2533 $seen_keys->{$import_key} = 1; # don't merge the same key twice
2543 $self->_source_handle($_[0]->handle);
2545 $self->_source_handle->resolve;
2549 =head2 throw_exception
2551 See L<DBIx::Class::Schema/throw_exception> for details.
2555 sub throw_exception {
2557 if (ref $self && $self->_source_handle->schema) {
2558 $self->_source_handle->schema->throw_exception(@_)
2565 # XXX: FIXME: Attributes docs need clearing up
2569 Attributes are used to refine a ResultSet in various ways when
2570 searching for data. They can be passed to any method which takes an
2571 C<\%attrs> argument. See L</search>, L</search_rs>, L</find>,
2574 These are in no particular order:
2580 =item Value: ( $order_by | \@order_by | \%order_by )
2584 Which column(s) to order the results by. If a single column name, or
2585 an arrayref of names is supplied, the argument is passed through
2586 directly to SQL. The hashref syntax allows for connection-agnostic
2587 specification of ordering direction:
2589 For descending order:
2591 order_by => { -desc => [qw/col1 col2 col3/] }
2593 For explicit ascending order:
2595 order_by => { -asc => 'col' }
2597 The old scalarref syntax (i.e. order_by => \'year DESC') is still
2598 supported, although you are strongly encouraged to use the hashref
2599 syntax as outlined above.
2605 =item Value: \@columns
2609 Shortcut to request a particular set of columns to be retrieved. Each
2610 column spec may be a string (a table column name), or a hash (in which
2611 case the key is the C<as> value, and the value is used as the C<select>
2612 expression). Adds C<me.> onto the start of any column without a C<.> in
2613 it and sets C<select> from that, then auto-populates C<as> from
2614 C<select> as normal. (You may also use the C<cols> attribute, as in
2615 earlier versions of DBIC.)
2621 =item Value: \@columns
2625 Indicates additional columns to be selected from storage. Works the same
2626 as L</columns> but adds columns to the selection. (You may also use the
2627 C<include_columns> attribute, as in earlier versions of DBIC). For
2630 $schema->resultset('CD')->search(undef, {
2631 '+columns' => ['artist.name'],
2635 would return all CDs and include a 'name' column to the information
2636 passed to object inflation. Note that the 'artist' is the name of the
2637 column (or relationship) accessor, and 'name' is the name of the column
2638 accessor in the related table.
2640 =head2 include_columns
2644 =item Value: \@columns
2648 Deprecated. Acts as a synonym for L</+columns> for backward compatibility.
2654 =item Value: \@select_columns
2658 Indicates which columns should be selected from the storage. You can use
2659 column names, or in the case of RDBMS back ends, function or stored procedure
2662 $rs = $schema->resultset('Employee')->search(undef, {
2665 { count => 'employeeid' },
2670 When you use function/stored procedure names and do not supply an C<as>
2671 attribute, the column names returned are storage-dependent. E.g. MySQL would
2672 return a column named C<count(employeeid)> in the above example.
2678 Indicates additional columns to be selected from storage. Works the same as
2679 L</select> but adds columns to the selection.
2687 Indicates additional column names for those added via L</+select>. See L</as>.
2695 =item Value: \@inflation_names
2699 Indicates column names for object inflation. That is, C<as>
2700 indicates the name that the column can be accessed as via the
2701 C<get_column> method (or via the object accessor, B<if one already
2702 exists>). It has nothing to do with the SQL code C<SELECT foo AS bar>.
2704 The C<as> attribute is used in conjunction with C<select>,
2705 usually when C<select> contains one or more function or stored
2708 $rs = $schema->resultset('Employee')->search(undef, {
2711 { count => 'employeeid' }
2713 as => ['name', 'employee_count'],
2716 my $employee = $rs->first(); # get the first Employee
2718 If the object against which the search is performed already has an accessor
2719 matching a column name specified in C<as>, the value can be retrieved using
2720 the accessor as normal:
2722 my $name = $employee->name();
2724 If on the other hand an accessor does not exist in the object, you need to
2725 use C<get_column> instead:
2727 my $employee_count = $employee->get_column('employee_count');
2729 You can create your own accessors if required - see
2730 L<DBIx::Class::Manual::Cookbook> for details.
2732 Please note: This will NOT insert an C<AS employee_count> into the SQL
2733 statement produced, it is used for internal access only. Thus
2734 attempting to use the accessor in an C<order_by> clause or similar
2735 will fail miserably.
2737 To get around this limitation, you can supply literal SQL to your
2738 C<select> attibute that contains the C<AS alias> text, eg:
2740 select => [\'myfield AS alias']
2746 =item Value: ($rel_name | \@rel_names | \%rel_names)
2750 Contains a list of relationships that should be joined for this query. For
2753 # Get CDs by Nine Inch Nails
2754 my $rs = $schema->resultset('CD')->search(
2755 { 'artist.name' => 'Nine Inch Nails' },
2756 { join => 'artist' }
2759 Can also contain a hash reference to refer to the other relation's relations.
2762 package MyApp::Schema::Track;
2763 use base qw/DBIx::Class/;
2764 __PACKAGE__->table('track');
2765 __PACKAGE__->add_columns(qw/trackid cd position title/);
2766 __PACKAGE__->set_primary_key('trackid');
2767 __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD');
2770 # In your application
2771 my $rs = $schema->resultset('Artist')->search(
2772 { 'track.title' => 'Teardrop' },
2774 join => { cd => 'track' },
2775 order_by => 'artist.name',
2779 You need to use the relationship (not the table) name in conditions,
2780 because they are aliased as such. The current table is aliased as "me", so
2781 you need to use me.column_name in order to avoid ambiguity. For example:
2783 # Get CDs from 1984 with a 'Foo' track
2784 my $rs = $schema->resultset('CD')->search(
2787 'tracks.name' => 'Foo'
2789 { join => 'tracks' }
2792 If the same join is supplied twice, it will be aliased to <rel>_2 (and
2793 similarly for a third time). For e.g.
2795 my $rs = $schema->resultset('Artist')->search({
2796 'cds.title' => 'Down to Earth',
2797 'cds_2.title' => 'Popular',
2799 join => [ qw/cds cds/ ],
2802 will return a set of all artists that have both a cd with title 'Down
2803 to Earth' and a cd with title 'Popular'.
2805 If you want to fetch related objects from other tables as well, see C<prefetch>
2808 For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
2814 =item Value: ($rel_name | \@rel_names | \%rel_names)
2818 Contains one or more relationships that should be fetched along with
2819 the main query (when they are accessed afterwards the data will
2820 already be available, without extra queries to the database). This is
2821 useful for when you know you will need the related objects, because it
2822 saves at least one query:
2824 my $rs = $schema->resultset('Tag')->search(
2833 The initial search results in SQL like the following:
2835 SELECT tag.*, cd.*, artist.* FROM tag
2836 JOIN cd ON tag.cd = cd.cdid
2837 JOIN artist ON cd.artist = artist.artistid
2839 L<DBIx::Class> has no need to go back to the database when we access the
2840 C<cd> or C<artist> relationships, which saves us two SQL statements in this
2843 Simple prefetches will be joined automatically, so there is no need
2844 for a C<join> attribute in the above search.
2846 C<prefetch> can be used with the following relationship types: C<belongs_to>,
2847 C<has_one> (or if you're using C<add_relationship>, any relationship declared
2848 with an accessor type of 'single' or 'filter'). A more complex example that
2849 prefetches an artists cds, the tracks on those cds, and the tags associted
2850 with that artist is given below (assuming many-to-many from artists to tags):
2852 my $rs = $schema->resultset('Artist')->search(
2856 { cds => 'tracks' },
2857 { artist_tags => 'tags' }
2863 B<NOTE:> If you specify a C<prefetch> attribute, the C<join> and C<select>
2864 attributes will be ignored.
2874 Makes the resultset paged and specifies the page to retrieve. Effectively
2875 identical to creating a non-pages resultset and then calling ->page($page)
2878 If L<rows> attribute is not specified it defualts to 10 rows per page.
2880 When you have a paged resultset, L</count> will only return the number
2881 of rows in the page. To get the total, use the L</pager> and call
2882 C<total_entries> on it.
2892 Specifes the maximum number of rows for direct retrieval or the number of
2893 rows per page if the page attribute or method is used.
2899 =item Value: $offset
2903 Specifies the (zero-based) row number for the first row to be returned, or the
2904 of the first row of the first page if paging is used.
2910 =item Value: \@columns
2914 A arrayref of columns to group by. Can include columns of joined tables.
2916 group_by => [qw/ column1 column2 ... /]
2922 =item Value: $condition
2926 HAVING is a select statement attribute that is applied between GROUP BY and
2927 ORDER BY. It is applied to the after the grouping calculations have been
2930 having => { 'count(employee)' => { '>=', 100 } }
2936 =item Value: (0 | 1)
2940 Set to 1 to group by all columns.
2946 Adds to the WHERE clause.
2948 # only return rows WHERE deleted IS NULL for all searches
2949 __PACKAGE__->resultset_attributes({ where => { deleted => undef } }); )
2951 Can be overridden by passing C<{ where => undef }> as an attribute
2958 Set to 1 to cache search results. This prevents extra SQL queries if you
2959 revisit rows in your ResultSet:
2961 my $resultset = $schema->resultset('Artist')->search( undef, { cache => 1 } );
2963 while( my $artist = $resultset->next ) {
2967 $rs->first; # without cache, this would issue a query
2969 By default, searches are not cached.
2971 For more examples of using these attributes, see
2972 L<DBIx::Class::Manual::Cookbook>.
2978 =item Value: \@from_clause
2982 The C<from> attribute gives you manual control over the C<FROM> clause of SQL
2983 statements generated by L<DBIx::Class>, allowing you to express custom C<JOIN>
2986 NOTE: Use this on your own risk. This allows you to shoot off your foot!
2988 C<join> will usually do what you need and it is strongly recommended that you
2989 avoid using C<from> unless you cannot achieve the desired result using C<join>.
2990 And we really do mean "cannot", not just tried and failed. Attempting to use
2991 this because you're having problems with C<join> is like trying to use x86
2992 ASM because you've got a syntax error in your C. Trust us on this.
2994 Now, if you're still really, really sure you need to use this (and if you're
2995 not 100% sure, ask the mailing list first), here's an explanation of how this
2998 The syntax is as follows -
3001 { <alias1> => <table1> },
3003 { <alias2> => <table2>, -join_type => 'inner|left|right' },
3004 [], # nested JOIN (optional)
3005 { <table1.column1> => <table2.column2>, ... (more conditions) },
3007 # More of the above [ ] may follow for additional joins
3014 ON <table1.column1> = <table2.column2>
3015 <more joins may follow>
3017 An easy way to follow the examples below is to remember the following:
3019 Anything inside "[]" is a JOIN
3020 Anything inside "{}" is a condition for the enclosing JOIN
3022 The following examples utilize a "person" table in a family tree application.
3023 In order to express parent->child relationships, this table is self-joined:
3025 # Person->belongs_to('father' => 'Person');
3026 # Person->belongs_to('mother' => 'Person');
3028 C<from> can be used to nest joins. Here we return all children with a father,
3029 then search against all mothers of those children:
3031 $rs = $schema->resultset('Person')->search(
3034 alias => 'mother', # alias columns in accordance with "from"
3036 { mother => 'person' },
3039 { child => 'person' },
3041 { father => 'person' },
3042 { 'father.person_id' => 'child.father_id' }
3045 { 'mother.person_id' => 'child.mother_id' }
3052 # SELECT mother.* FROM person mother
3055 # JOIN person father
3056 # ON ( father.person_id = child.father_id )
3058 # ON ( mother.person_id = child.mother_id )
3060 The type of any join can be controlled manually. To search against only people
3061 with a father in the person table, we could explicitly use C<INNER JOIN>:
3063 $rs = $schema->resultset('Person')->search(
3066 alias => 'child', # alias columns in accordance with "from"
3068 { child => 'person' },
3070 { father => 'person', -join_type => 'inner' },
3071 { 'father.id' => 'child.father_id' }
3078 # SELECT child.* FROM person child
3079 # INNER JOIN person father ON child.father_id = father.id
3081 If you need to express really complex joins or you need a subselect, you
3082 can supply literal SQL to C<from> via a scalar reference. In this case
3083 the contents of the scalar will replace the table name asscoiated with the
3086 WARNING: This technique might very well not work as expected on chained
3087 searches - you have been warned.
3089 # Assuming the Event resultsource is defined as:
3091 MySchema::Event->add_columns (
3094 is_auto_increment => 1,
3103 MySchema::Event->set_primary_key ('sequence');
3105 # This will get back the latest event for every location. The column
3106 # selector is still provided by DBIC, all we do is add a JOIN/WHERE
3107 # combo to limit the resultset
3109 $rs = $schema->resultset('Event');
3110 $table = $rs->result_source->name;
3111 $latest = $rs->search (
3114 (SELECT e1.* FROM $table e1
3116 ON e1.location = e2.location
3117 AND e1.sequence < e2.sequence
3118 WHERE e2.sequence is NULL
3123 # Equivalent SQL (with the DBIC chunks added):
3125 SELECT me.sequence, me.location, me.type FROM
3126 (SELECT e1.* FROM events e1
3128 ON e1.location = e2.location
3129 AND e1.sequence < e2.sequence
3130 WHERE e2.sequence is NULL
3137 =item Value: ( 'update' | 'shared' )
3141 Set to 'update' for a SELECT ... FOR UPDATE or 'shared' for a SELECT